Rotary control switch



Oct. 27, 1931.

G. W. O KEEFFE ROTARY CONTROL SWITCH Filed July 20.

WHHI I Patented Oct. 27, 1931 UNITED STATES PATENT OFFICE GEORGE W. OKEEFFE, OF MILTON, MASSACHUSETTS, ASSIGNOR TO CONDIT ELECTRICAL MANUFACTURING CORPORATION, OF SOUTH BOSTON, MASSACHUSETTS, A CORPORA- TION OF MASSACHUSETTS ROTARY CONTROL SWITCH Applicationfiled July 20,

This invention relates to rotary switches especially adapted to control electro-magnetir :allyoperated switches used on electric nictor circuits although not necessarily restricted to such use.

One of the objects of the present invention is the provision of a small and inexpensive rotary control switch which is especially adapted to be carried by the cover of and lo- 11 l n the enclosing casing of the elecic switch and connected wi 11 the operating means thereof.

A further object of the invention is the provision of a rotary control switch which is adapted to be moved in opposite directions aws from a normal or neutral position to contro. respectively the closing and opening of the ciecitro-anagnetic switch and which will automatically return to the neutral position when released.

A further object of the invention is the provision of a rotary control switch having a single spring which biases the switch to re turn to a neutral position when moved in either of two opposite directions away from sucl'i position.

Another object of the invention is generally to imprmc the construction and operation of rotary control switches.

Fig. 1 is a side elevation of a switch embodying the present invention. 1

Fig. 2 is a plan view of the switch of Fig. 1.

Fig. 3 is a section taken along line 33 of Fig. 1.

Fig. 4 is a sectional detail taken along line di -4'. of Fig. 2.

Fig. 5 is a perspective view of the supporting base of the switch.

Fig. 6 is a diagram of the circuit connections between the rotary control switch and the electro-magnetic switch. a

Fig. 7 is a view of the contact members with the rotary bridging plate in position to close the closing circuit of the electromagnetic switch.

Fig. 8 is a view similar to Fig. 7 but with the rotary bridging plate in position to open the holding circuit of the electro-magnetic switch.

The switch here shown includes an insu- 1929. Serial No. 379,744.

lating base 10 which preferably is made of molded insulating material. The base is generally rectangular in shape and is provided with upper and lower bosses 12 that project forwardly from its front face and are adapted to bear upon and support the base in spaced relation with the inner face of a supporting plate 14, which plate may constitute the cover or casing of the electro-magnetic switch which the switch of this invention is particularly adapted to control. Attaching screws 16 are passed through said plate 14 and through said bosses 12 and are screw threaded into nuts 18 whereby to hold the base 10 in position on said plate 14. Said nuts 18 are received in recesses in the rear face of said base, the opposite side walls of which recesses engage the opposite side faces of said nuts and hold them against rotation.

The base 10 is provided in the middle thereof and between the bosses 12 with a metal bushing 22 which is fixed rigidly in said plate and is preferably moulded therein and outstands in opposite directions beyond the front and rear faces of said base. A square shaft 24 is rotatably received in and supported by said bushing and has a knob 26 fixed removably to the outer end. thereof by a screw 28. Said knob has a reduced shank 30 which extends loosely through an opening in the cover plate 14. A rotary bridging member consisting of a conducting plate or disc 32 has a square aperture therein which is conformed with the cross sectional dimensions of said shaft and in which said rear end of said shaft is received thereby establishing a rotary driving connection between the shaft and plate. The plate overlies the rear end of the bushing 22 and is fixed against detachment from the end of the shaft by a screw 34 which is threaded in and overlies the end of the shaft and the plate. A washer 36 is received on the forward end of the shaft between the knob 26 and the forward end of the bushing and is held against forward axial displacement by means of a cotter pin 38, whereby to cooperate with the plate 32 in holding the shaft against undue axial movement in both directions.

, The shaft and disc are held yieldingly in a normal position against rotary movement in opposite dire tions by a spiral or coil spring ll), the convolutions of which loosely encircle the forwardly projecting end of the bushing 22 between the front face of the supporting and the washer 36, which washer also means to hold said spring in place. rlllg has overlapping ends or arms 42 and which are disposed on opposite sides of and normally bear against an upstanding projection 46 of the lower boss 12. A pin 48 is fixed rigidly in the bridging plate 32 and extends forwardly through an arcuate slot in the base 10 under the bushing 22 and intothe space between the two ends of the spring. The diameter of the pin 48 closely contorms with the dimensions of the space between the ends of the spring so that the plate 38 is held by the spring in a normal or mid position unless intentionally moved herefrom. The tension on the spring is such hat the spring-ends tend to move in oppoite directions, the right-hand end to the left .nd the left-hand end to the right. lVhen he shaft 2-l is rotated in one direction as clockwise, Fig. 8, the pin engages the end 44 of the spring and moves it away from the projection it), the other end of the spring bearing against said projection. When the shaft is rotated in the opposite direction, the pin engages the end 4-2 of the spring and the other end it then bears against the projection Thus, the spring tends to return the bridging plate 32 to its normal position when it is rotated away from such position in either direction.

The rotation of the shaft and plate in a clockwise direction is adapted to deenergize the electro-magnetic holding means for the switch and to cause the switch to open. The rotation of the plate in a counter-clockwise direction from its normal position is arranged to initially energize the magnetic holding means for the switch and thereby cause it to close. The extreme operated positions of the bridging plate are determined by engagement of the pin 48 with the end walls of the arcuate slot 50. The bridging plate 32 is provided with a short peripheral contact face and an opposite long peripheral contact face it with a notch 56 of short arcuate extent between said contact faces in one side of the plate and an opposed notch 58 of long arcuate extent in the other side of the plate. The notches provide recesses in which the contact members cooperating with the bridging plate are adapted to be located when they are electrically disconnected from the plate by movements thereof. Three resilient stationary contact members 60 62 and 64 are fixed to the rear face of the base 10 and are provided with clamping terminals 66 to which circuit conductors are adapted to be connected. Said resilient contact members are disposed about the periphery of the bridging plate, the contact ends of the members 62 and 64 being relatively close together while the contact end of the member 60 is approximately diametrically opposed to the contact ends of the aforesaid contact members. The arrangement is such that when the bridging plate 32 is in its normal position, the contact member 60 engages the contact section 54 of the plate and the contact member 62 engages the contact section 52, while the contact member 6a is opposite the long notch 58 and thus is free from the plate. lVhen the plate is rotated in a counter-clocl-rwise direction, looking from the front of the switch to its extreme position in this direction, the bridging plate 32 is disposed as shown in Fig. 7 wherein all of the contact members are in engagement therewith. This is the position adapted for the closing of the electro-magnetic switch and the starting of the motor controlled thereby. When the bridging plate is rotated into its extreme position in the opposite direction, the notch 56 is adapted to be disposed opposite the contact member 60 and the notch 58 is adapted to be disposed opposite the contact members 62 and 64, all of which contact members are thus insulated from the plate. This is the position adapted for the opening of the electro-magnetic switch and the stopping of the motor controlled thereby.

The circuit connections between the corn trol switch and the electro-magnetic switch are illustrated in Fig. 6.

The electro-magnetic switch has the mow able member 68 which bridges the stationary switch terminals 70 that are included in serice with one side of the motor circuit 71. The switch is closed by the electro-magnct having the actuating windi 72, one terminal of which is connected t he other side of the motor circuit. The stationary contact member 60 is connected to the remain ing end of the actuating winding. The contact member 6d is connected to that side of the motor circuit in which the stationary switch terminals are included and the contact member 62 is connected through a flexible. lead 'ith the bridging member 68. Thus. when the rotary bridging plate 32 is rotated in counterclockwise direction, looking from the front of the switch, the circuit for the winding 72 will be completed through h contact members 60 and 64-. and the bridging plate 32. When the electromagnetic swi is closed the circuit for the e retro-magin. is also completed through the bridging member 68 of the electro-magnctic switch and the contact member 64. The knob of the control switch can. then be released and the bridging plate will return to its normal position under action of i s spring while leaving the electro-magnetic switch closed.

hen the bridging plate is rotated in the opposite direction, the circuit through the electro-magnet will be interrupted at the contactmember 60 and also at the contact member 62 so that the electro-magnetic switch will open; and it willstay open when the rotary bridging plate returns to its normal position.

I claim: I

1. A rotary control switch including a rotary bridging disc having means for holding it yieldingly in a normal position and for returning it to such position when moved in either direction therefrom, said disc having opposed short and long peripheral contact faces and opposed short and long notches interposed between said contact faces, and three ined contact members peripherally disposed. about said contact disc and engageable therewith, two of said contact members being close together and the third contact member being approximately diametrically opposed thereto, said plate holding means being arranged to position said plate normally in engagement with said third contact member and one of said other contact members, and said plate being movable in one direction to break engagement with said third contact member and in the opposite direction to make engagement with all three con tact members.

2. A rotary control switch having a rotary bridging plate, means to hold said bridging plate in a normal position and to return it to said position when it is rotated in either direction therefrom. and three stationary contact members peripherally spaced about and arranged for engagement with said. plate, two of said contacts being engageable therewith when it is in normal position, all being engageable with said plate when it rotated in one direction from normal, and two being free from said plate when it is rotated in the opposite direction from normal.

3. A rotary control switch including a r0- tary bridging plate having opposed short and long peripheral contact faces and opposed short and long notches interposed between said contact faces, three fixed contact members cooperating with said bridging plate and arranged peripherally thereabout, said bridging plate having a normal position and operated positions on opposite sides of said normal position, two of said contact members being in engagement respectively wi h said long and short contact faces when said bridging plate is in the normal position and the other contact member being disposed opposite said long notch, all three of said contact members being engaged with said bridging plate when it is moved in one direction from normal and two of said contact members being disposed in said notches and free from engagement with said plate when said plate is moved in the opposite direction from normal, means to rotate said plate in opposite directions, and means to return said plate to normal position when it is rotated away therefrom in either direction.

4. A rotary control switch including a rotar shaft, a bridging plate carried thereby an rotatable therewith, a plurality of contact members selectively engaged by said bridging plate during rotary movements thereof in opposite directions, a pair of said contact members being engageablc therewith when it is in normal position, all being ongageable therewithwhen it is rotated in one direction, and at least one of said pairs being free from said plate when it is rotated in the opposite direction from normal, and a spring surrounding said shaft having means to hold it yieldingly in a normal position and also to return it to said position when it is rotated in opposite directions therefrom.

5. A rotary control switch having a rotary shaft, a bridging plate carried thereby and rotatable therewith, fixed cont ct members selectively engaged by said plate diir ing rotary movements thereof in opposite directions, a pair of said contact members being cngageable therewith when it is in normal position, all being engageable therewith when it is rotated in one direction, and at least one of said pairs being free from said plate when it is rotated in the opposite direction from normal, a coil spring surrounding said shaft having crossed proximate ends, an abutment interposed between the ends of said spring and said shaft and constituting ,a support for said spring-ends, a plate having a driving projection which is located between said ends, and means to rotate said shaft whereby to cause said projection to engage and move each spring-end separately upon rotation of said shaft in opposite directions.

6. A rotary control switch having a rotary shaft, a bridging plate carried thereby and rotatable therewith, fixed contact members selectively engaged by said plate during rotary movements thereof in opposite directions,,a coil spring surrounding said shaft having crossed proximate ends, an abutment interposed between the ends of said spring and said shaft and constituting a support for said spring-ends, a plate having a driving projection which is located between said arms, means to rotate said shaft whereby to cause said projection to engage and move each spring-end separately upon rotation of said shaft in opposite directions, and means supporting said spring independently of said shaft and in co-axial relation therewith.

' 7. A rotary control switch having a rotatable shaft, a bridging plate carried thereby and rotatable therewith, contact members selectively engaged by said bridging plate during the rotary movements thereof in opposite directions, said plate having a projection which overlies said shaft, a coil spring surrounding said shaft having crossed ends between which said projection is received, a fixed abutment located between and engaged on opposite sides by said spring ends and constituting supporting means therefor, means to rotate said shaft in opposite directions whereby to urge said projections separately against both of said spring ends and to move them separately away from said abutment.

8. A rotary control switch including a supporting base having a bushing therein, a shaft rotatably received in said bushing having a square rear end extended rearwardly of said bushing, a bridging plate having a square aperture in which the square end of said shaft is received, said bridging plate overlying the rear end of said bushing, means carried by said shaft overlying the rear face of said bridging plate, fixed contact members carried by said base selectively engaged by said bridging plate during rotary movements thereof in opposite directions, a washer carried by the forward end of said shaft and overlying the forward end of said bushing and having means affixing it to said shaft against axial movement thereof in one direction, and a shaft-rotating knob fixed to said shaft forwardly of said washer.

9. A rotary control switch including a supporting base having a bushing therein which projects beyond opposite faces of said plate, a square shaft rotatable in said bushing and extended in opposite directions therethrough, a rotary bridging plate having a square aper ture in which the rear end of said square shaft is received whereby to connect said plate and shaft for conjoint rotation, means carried by said shaft engageable with said plate to secure it thereon against axial displacement in one direction, means located on the other end of said shaft engageable with said bushing and cooperating with said bridging plate to restrain said shaft from axial movement in both directions, a shaft-rotating knob fixed to the forward end of said shaft, a plurality of fixed contact members carried by said base and peripherally disposed about and selectively engaged by said bridging plate during rotary movements thereof in opposite directions, and means to hold said bridging plate in a normal position and to return it to said position when rotated in opposite directions therefrom including a coil spring encircling said bushing having crossed ends extended in the same direction, said base having an abutment located between said ends and normally holding them against angular movement in opposite directions, said bridging plate having a projection which extends through an arcuate slot in said base and is interposed between said spring ends and is arranged to move said ends separately away from said abutment when said shaft is rotated in opposite directions.

10. A rotary control switch including a base, having apair of spaced supporting bosses outstanding from the front face thereof, a bushing fixed in and outstanding from said base between said bosses, a shaft rotatably received within said bushing and er:- tended in opposite directions therebeyond, a bridging plate carried by one end of said shaft in confronting relation with the rear face of said base, an actuating knob fixed to the front end of said shaft between said bosses, a coil spring encircling said bushing having crossed ends which extend toward one of said bosses, said boss having a projection which is located between said spring ends and restrains them against angular mcvement in one direction, said bridging plate having a projection which extends through an arcuate slot in said base between one of said projections and said bushing and is received between said crossed spring ends and is ar'anged to engage each end separately and move it awa from said projection during rotary movements of said bridging plate in opposite directions.

In testimony whereof, I have signed my name to this specification.

GEORGE \V. OKEEFFE. 

